..Of particular interest was the effect of intelligibility on the most comfortable loudness (MCL) component of acceptable noise level (ANL)...

Most comfortable listening levels, background noise levels, and acceptable noise levels for children and adults with normal hearing

Robert MooreDepartment of Speech Pathology and Audiology, University of South Alabama, Mobile, AL, USAJ Am Acad Audiol 22:286-93. 2011

..ANL is calculated as the difference between most comfortable listening level (MCL) and background noise level (BNL). No studies have made direct comparisons of these measures between adults and children...

Effects of reverberation on acceptable noise level measurements in younger and older adults

Robert E MooreDepartment of Speech Pathology and Audiology, University of South Alabama, Mobile, AL 36688 0002, USAJ Voice 22:399-407. 2008

..One possible implication of this study is that differences in matching the pitch of one's own voice compared to matching other stimuli types may help to differentiate the source of singing inaccuracy (motor vs discrimination skills)...